Changes in Microstructure, Mechanical Properties, and Electrical Conductivity of Severely Drawn AA1070 Wire with Annealing

The drawing process severely deforms commercial AA1070 alloy for electrical wire, reducing a rod from a diameter of 2.0 mm to 0.4 mm, followed by annealing. The annealing process was conducted at various temperatures ranging from 200oC to 450oC, with each temperature maintained for 1hour. The effects of increasing annealing temperature on the microstructure, mechanical properties, and electrical properties of the Al wire were investigated in detail. The drawn Al wire showed a severely deformed microstructure and fiber texture that {110}<111> and {112}<111> components strongly developed. As the annealing temperature increased, the deformation structure changed into recrystallization structure over all regions. However, the fiber texture still strongly remained even in the specimens annealed at higher temperatures. The hardness decreased with increasing annealing temperature due to the occurrence of recovery and/or recrystallization. The strength also continued to decrease as the annealing temperature increased. However, elongation gradually increased with increase of annealing temperature to 250oC; above 275oC, it increased particularly sharply. The electric conductivity tended to increase slightly with increasing annealing temperature, reaching a maximum value of 62.2%IACS at 300oC. Changes in microstructure, mechanical properties and electrical conductivity with annealing of commercially drawn AA1070 were compared with those of the previous study.